Self-sustainable charging station relies on micro smart grid

By Tereza Pultarova

Published Wednesday, March 5, 2014

German researchers are developing mass-charging station for electric vehicles fully powered by renewable resources

Said to be Germany’s biggest charging station, the facility at the Fraunhofer Institute Centre in Stuttgart is supposed to accommodate 30 electric vehicles at the same time and fully charge them in less than 20 minutes.

The station is connected to a micro smart grid managing the electricity demand and supply.

“Charging an electric vehicle fleet poses high requirements on the energy system,” said Hannes Rose, head of the Mobility Innovation Lab at the Fraunhofer Institute of Industrial Engineering IAO. “Setting up an EV charging infrastructure of this kind is impossible without smart charging and load management.”

The team led by Rose is currently fine-tuning the micro smart grid to be able to rely solely on renewable resources. They will soon install a photovoltaic unit and a small wind turbine at the facility and equip the system with a lithium-ion battery storage unit, plus a roof-mounted redox flow battery serving for temporary energy storage.

If the need arises, the micro smart grid powering the charging station could always be connected to the regular electrical grid.

However, the researchers believe that producing energy locally, independently on the centralised grid is the way forward.

“Wind and photovoltaic facilities generate electricity intermittently, which doesn’t always match customer demand,” said Rose. “The grid has to compensate for these fluctuations, increasing the risk of power outages. We can counteract this risk by establishing decentralized supplies of electricity and by optimizing the way we manage our energy. And doing so also serves to increase our independence from energy price trends by largely eliminating the need to import electricity.”